Published · Aurelis Peptides
Tirzepatide and semaglutide are different peptide molecules. Tirzepatide activates GIP and GLP-1 receptors; semaglutide activates the GLP-1 receptor. Both appear in weight-loss research, and published trials have compared them directly.
The useful question is which comparison you are reading. SURMOUNT-5 examined weight change in adults with obesity without type 2 diabetes. SURPASS-2 centred on blood-sugar control in adults with type 2 diabetes. Those are different study questions.
Tirzepatide vs semaglutide at a glance
| Compare | Tirzepatide | Semaglutide |
|---|---|---|
| Receptor targets | GIP and GLP-1 | GLP-1 |
| Common description | Dual-receptor agonist | GLP-1 receptor agonist |
| Direct comparisons discussed here | SURMOUNT-5 and SURPASS-2 | |
| Current Aurelis entry | 30 mg / 40 mg / 50 mg / 60 mg per unit | No listed catalogue entry |
Dual versus single: what does that mean?
A receptor is a target through which a signal affects a cell. An agonist activates that target. GIP means glucose-dependent insulinotropic polypeptide; GLP-1 means glucagon-like peptide-1.
The original tirzepatide research described LY3298176 as one peptide acting at both GIP and GLP-1 receptors. It is not a mixture of two separately supplied peptides. Semaglutide's discovery paper describes a modified GLP-1 analogue. These molecular profiles explain the dual-versus-single wording. Tirzepatide discovery paper · Semaglutide discovery paper.
Two direct trials, two different questions
| Trial | Participants | Length | Main measurement |
|---|---|---|---|
| SURMOUNT-5, 2025 | 751 adults with obesity, without type 2 diabetes | 72 weeks | Percentage change in body weight |
| SURPASS-2, 2021 | 1,879 adults with type 2 diabetes | 40 weeks | Change in glycated haemoglobin, HbA1c |
Both were randomised, open-label trials: the groups were assigned by chance, and the assigned treatment was known. The SURMOUNT-5 report and SURPASS-2 report give the full study designs.
What did SURMOUNT-5 find about weight loss?
The reported least-squares mean weight reductions at week 72 were 20.2% with tirzepatide and 13.7% with semaglutide. Tirzepatide also produced a greater reduction in waist circumference in that trial. The most common adverse events in both groups were gastrointestinal, mostly mild to moderate. Read the primary SURMOUNT-5 results.
The difference between those weight figures is 6.5 percentage points. It is not 6.5 kilograms, and the group averages do not predict an individual's result. The findings belong to the specified clinical preparations, participants and study conditions.
Why does SURPASS-2 appear in the same comparison?
SURPASS-2 investigated a different primary endpoint: HbA1c, a measure used to assess longer-term blood-sugar levels. Participants had type 2 diabetes inadequately controlled with metformin. The three tirzepatide groups had greater HbA1c reductions than the semaglutide group; weight reductions were also greater. Gastrointestinal events were the most common adverse events. Read the primary SURPASS-2 report.
A blood-sugar endpoint and a weight endpoint answer related but separate questions. Do not merge the two trials into one result. Read the population, formulation, comparison and safety findings together when evaluating either paper.
Where does retatrutide fit?
Retatrutide is another molecular identity, not an alternative name for either entry above. Our retatrutide vs tirzepatide guide covers that comparison separately. The retatrutide vs semaglutide guide discusses its selected studies without treating separate placebo trials as a direct contest.
For tirzepatide's wider weight, appetite and blood-sugar research context, read the individual Tirzepatide guide. This page focuses on the direct tirzepatide-semaglutide comparisons.
What does Aurelis list?
Aurelis lists Tirzepatide 30 mg / 40 mg / 50 mg / 60 mg per unit. Semaglutide is included here for scientific comparison and has no current Aurelis catalogue entry.
Those mg figures describe product content, not a dose, liquid concentration or clinical-trial preparation. A larger catalogue unit does not reproduce a trial group. The content and concentration guide explains the distinction.
Prepare a precise product enquiry
Both vials and pen-style kits remain part of the format conversation. Include Tirzepatide, the selected listed content, unit count, preferred presentation and destination in Australia, Canada or the USA. The team confirms current local availability and the complete offered specification.
Ask for the matching identity, content and batch documents. Published clinical research does not verify a supplied Aurelis batch or establish its treatment performance. Send a Tirzepatide enquiry or email sales@aurelispeptides.com.
Primary research sources
- Coskun et al., Molecular Metabolism, 2018 — the single-peptide dual GIP/GLP-1 receptor profile of LY3298176.
- Lau et al., Journal of Medicinal Chemistry, 2015 — the molecular development of semaglutide.
- Aronne et al., SURMOUNT-5, New England Journal of Medicine, 2025 — the direct weight-change comparison.
- Frías et al., SURPASS-2, New England Journal of Medicine, 2021 — the direct type 2 diabetes trial.